Bishop Hill Stocker in Oxford
May 12, 2012 Climate: IPCC Simon Anthony sends this report of Thomas Stocker's recent talk in Oxford.
Yesterday I attended a talk at Wolfson College, Oxford by Thomas Stocker, co-chair of the IPCC's AR5 WG1 on "Climate Change: Making the best use of scientific information". He's an intelligent, well-mannered and rational man, in a position of great influence. It's therefore all the more concerning to see the weakness of the evidence and arguments which have, it seems, convinced him of the reality and urgency of AGW and which he feels should convince everyone else.
Now one wouldn't expect the head of an IPCC working group to pour scorn on the evidence for AGW (after all, the Pope is unlikely to ask Richard Dawkins to write one of his encyclicals to the faithful). However, while nothing he had to say was novel, I think it's reasonable to assume that Prof Stocker brought along the very best evidence he had, not leaving the really good arguments back at home. So it's all the odder that what he had to say was so weak.
He told us that the IPCC's unequivocal view was that the climate had got warmer. He seemed to think that sceptics would disagree with this. (I suppose some might, but not many, so the statement rather obviously begs questions of speed, typicality and relative importance of the various causes.)
His main concern was with communicating key information so that non-specialists (public and policy makers) reached the same conclusions that he and his colleagues had. He therefore showed three graphs, of global temperature, sea level and snow cover which he thought were conclusive. The charts were all from AR4's Summary for Policy Makers and it's true they all showed the behaviour you'd expect in a warming world. Unfortunately the start dates for the data sets were 1850, 1870 and 1920 respectively, so giving no comparison with longer term behaviour and all therefore again begging the obvious questions.
He discussed the uncertainty in "forecasts" from various "scenarios" (or whatever they're called in climate science-speak) for future temperatures up to 2100. He described the difficulty in explaining the uncertainty in these "predictions" (I'm stuck in Oldspeak) due to the variations between and within the models. These included parameters, initial conditions, physical processes, natural variability, economic assumptions and so on. These factors were combined together "mathematically" and then subject to "expert" interpretation before being delivered to policy makers.
It was striking that not once did he suggest that the models' uncertainties (or "errors" in Oldspeak) should be established by comparing their "predictions" against measured data. The only sources of uncertainty with which Prof Stocker seemed concerned were between and within models. It seemed comparison with what was supposedly modelled was not relevant.
There was another troubling note in that Prof Stocker referred several times to "deniers". It was, at the very least, unfortunate that a man of such seniority should look on those who disagree with his views in such terms. It struck a discordant note from a man who otherwise seemed polite. It was also ironic in that he said that he and his colleagues mustn't respond in equivalent terms to the "provocations" of climate change deniers. (He seemed put out that he'd had to spend "several hours" responding to FOI requests. Apparently these mostly came from the UK - I don't know who's doing it, but keep it up. To his credit - or at least not adding to his debits - he did say, albeit reluctantly, that climate scientists should continue properly to respond to such requests.)
Also to his credit - or at any rate avoiding an obvious trap - in response to a question he insisted that scientists shouldn't take activist roles and shouldn't be influenced by WWF, Greenpeace or Heartland.
Something which has constantly surprised me is how otherwise intelligent and rational people can come to believe strongly in something for which the evidence is either lacking or, in some cases, absent. I suppose the most striking example is Newton who, judging by the amount of work he devoted to it, attached far more importance to alchemy than science and mathematics. I suppose in Newton's case it might have been, at least in part, because he lived quite an isolated life and didn't discuss his work much with others.
Now obviously the weakly grounded beliefs of modern climate scientists aren't in the Newtonian league (and nor, equally, is their work) but they do seem to have very strong beliefs based on weak or equivocal evidence. Of course they don't tend to spend their time in hermit-like isolation (see below) but they seldom if ever are obliged to engage directly with lucid sceptics. So I wonder if the reason for the strength of climate scientists' weakly supported beliefs is that not only are they similar to Newton in that they seldom or never face opposition, but they constantly reinforce one another's beliefs.
I also wonder (hope?) if, in some more rational future, "AGW" will be investigated mainly by psychologists as a powerful example of a recurrent and damaging aspect of human behaviour.
Oh, and this is somewhat BTW, and possibly unfair, but I looked at the website for WG1 and came across a list of the meetings and workshops for the group. The noble men and women in WG1 have, since 2009, endured travel to and stay in the following locations: Honolulu, Oslo, Venice, Geneva, Bali, Panama, Boulder, Hanoi, Kuala Lumpur, Stanford, Belgium (hmmm, someone slipped up), Geneva again, Kunming (China), Okinawa, Gold Coast (Australia), Lima, Brest, Kampala and Marrakech. They are plainly terrified of the effect of all those CO2 emissions.
Reader Comments (118)
Groupthink has been discussed very widely recently.
"The noble men and women in WG1 have, since 2009, endured travel to and stay in the following locations: Honolulu, Oslo, Venice, Geneva, Bali, Panama, Boulder, Hanoi, Kuala Lumpur, Stanford, Belgium (hmmm, someone slipped up), Geneva again, Kunming (China), Okinawa, Gold Coast (Australia), Lima, Brest, Kampala and Marrakech."
I have often wondered if these "scientists" would be quite so committed if all the meetings were held in a guest house in Blackpool.
"Podcasts of the lectures will be available from Wolfson Podcasts over the coming weeks."
Apparently, this includes Stocker's.
I too am always puzzled why they "leave the good evidence at home" and lead with weak and often easily-refuted stuff instead.
One example is Al Gore's description of pacific islanders being evacuated to New Zealand as their island sank beneath the rising seas. The problem is that this never happened. So why did he stir this nonsense into the mix ? What else is he lying about ?
Or this gem from the IPCC:
It's hard to see what on earth this means. More squirrels ? Fewer squirrels ? Bigger squirrels ? Hungrier squirrels ? Remember they claim this is strong evidence of man-bear-pig - yet us little people don't even know what it means.
Wasn't it Jones who when asked a series of questions posted on the BBC had to admit that it all boiled down to
'We can't think of anything else so we are left with CO2'
http://news.bbc.co.uk/1/hi/8511670.stm
H - If you agree that there were similar periods of warming since 1850 to the current period, and that the MWP is under debate, what factors convince you that recent warming has been largely man-made?
The fact that we can't explain the warming from the 1950s by solar and volcanic forcing - see my answer to your question D.
So it is all down to a bit of warming since the LIA and the output of computer models?
But they refuse to tell us how the models work. To me this is the same as the priests of the middle ages who refused to allow the Bible to be translated into English, lest they lose their monopoly in interpreting the (supposed) true words of God.
The real explanation does not involve CO2 but to get to it you have to correct Sagan's incorrect aerosol optical physics, used by the IPCC as a crutch to explain no present warming.
[3.5% reduction of cloud albedo replaces part or all of the 2.88 W/m^2 higher 'forcing' attributed by the IPCC to GHG-GW from the Last Glacial Maximum to the pre-industrial period.]
Hi Simon
Just to be clear, the list of WG1 meetings and workshops that you quote is all of meetings relevant to WG1, which some WG1 authors / chairs / Technical Support Unit members have attended. It doesn't mean that all the WG1 authors attend all, or even most, of the meetings. The majority of authors will have attended only the 3 Lead Author meetings (Kunming, Brest, Marrakech).
Also I should point out that this is an international activity with authors from all round the world, so most people will be travelling wherever the meetings are held. So holding the meeting in Blackpool would still mean the majority of authors have to fly!
This is precisely why I never go round telling people they shouldn't fly. Air travel is an essential part of modern society.
Cheers
Richard
@martin brumby
"The noble men and women in WG1 have, since 2009, endured travel to and stay in the following locations: Honolulu, Oslo, Venice, Geneva, Bali, Panama, Boulder, Hanoi, Kuala Lumpur, Stanford, Belgium (hmmm, someone slipped up), Geneva again, Kunming (China), Okinawa, Gold Coast (Australia), Lima, Brest, Kampala and Marrakech."
I have always found it very amusing that the 'Sea Level Research Group' is located in Boulder. Colorado. Boulder has an elevation of 5,430 feet, and is about as far from any sea as it is possible to get in the entire USA.
Richard Betts: “Air travel is an essential part of modern society”.
I think we know that. Why does Professor Betts come here to tell us that? Why not write an article on Guardian Environment saying the same thing? They pay, and, given the number of times they’ve quoted him in the past, I’m sure they’d love to have him.
And, to crown it all, they’d find the message deeply controversial.
But the models are demonstrably wrong, being based on an incorrect radiative heat transfer appearing to originate from Houghton, offset mainly by doubled real low level cloud optical depth.
Steve McIntyre had a post about Stocker recently.
Flying to Honolulu would be very evil because the CO2 levels for the entire planet are measured in nearby Moana Loa. Just imagine if they take the reading just as your plane passes.
My eco-friend Megan once told me that flying is the worstest possible way of producing CO2 because
1) The CO2 is produced nearer to the atmosphere (boo) and
2) Flying is growing much faster than other activities that produce CO2 (hiss)
Yes this is the same Megan that wants to leave a nicer world for her children by not having children.
@ Latimer Alder: I suppose if you are an activist convinced that sea level rise is going to drown the world's major cities then being a mile above the water makes perfect sense.
Richard Betts: “Air travel is an essential part of modern society”.
I agree, so is a supercomputer to forecast the wettest drought since records began
http://www.metoffice.gov.uk/media/pdf/p/i/A3-layout-precip-AMJ.pdf
'His main concern was with communicating key information '
Still flogging this very dead horse, its not the way the message is given its the actual validity of the message in the first place .
As for 'deniers ' I wonder could Stocker give a scientific, not religions nor philosophical , definition of what that is supposed to mean ?
'He seemed put out that he'd had to spend "several hours" responding to FOI requests. '
Fine, if he does not want to follow the rules of the role then don't take the job nor the money that comes with it either.The childish use of 'deniers' , by the way has Stocker ever found anyone that claims that climate does not change . means his not really due any slack .
KnR: for deniers, look no further than the warmists who insist that prior to Man, the Holocene climate was effectively unchanging with time.
Your much appreciated report strikes several chords with me, but let me mention just two:
(1) I had the same feeling at St Andrews the other month after listening to Prof Tom Crowley who has served as an IPCC reviewer, and remains in thrall to the output of the IPCC. He too presented such graphs and seemed to feel they were convincing. It was as if his critical faculty had been somehow numbed by them. There was nothing he said in support of acute concern about CO2 etc that could not admit of considerable discussion and reservation, yet for him they were like rabbits out of a hat, to be displayed by a conjuror to the amazement of all.
(2) Quote from above post ‘I also wonder (hope?) if, in some more rational future, "AGW" will be investigated mainly by psychologists as a powerful example of a recurrent and damaging aspect of human behaviour.’ I agree with this. It is not an easy thing to say since it risks looking like a cheap debating tactic, but I do believe that the best thing that could emerge from this shameful period in science and politics is an improved understanding of how patently competent people come to be not just swept along by a point of view, but actively promote it, when the supporting evidence is so weak, or indeed absent, and in circumstances where this p of v promises to be (and now can be seen as being) enormously influential. Even better, would be if this insight was such that we would be appreciably less likely to see this kind of thing again since a great deal of avoidable loss, suffering and waste has already been caused by it, and I suppose the bill is by no means yet complete.
@ZDB
'In fact, some of the climategate enquiries reproduced the models in about 2 days'
So how come it's taken some of the' world finest' modellers thirty odd years and many billion dollars to create them? If it can truly be done by 'amateurs' in a couple of days I fear we have been vastly overcharged and undersupplied by the climatologits.
Richard Betts any good reason such events could not be held in places like Blackpool , apart that is form the lack of 5 start Hotels or Michelin Restaurants. For its amazing how this conferences seem to need very good hotels and restaurants, payed for by the taxpayer , to produce their 'wonders '
May 12, 2012 at 10:19 AM | Richard Betts
"So holding the meeting in Blackpool would still mean the majority of authors have to fly!
This is precisely why I never go round telling people they shouldn't fly. Air travel is an essential part of modern society."
OK, that's good.
So, no problem with refining my modest proposal:- How about January in Pyramiden.
http://en.wikipedia.org/wiki/Pyramiden
Be good to check out how the disappearing ice & polar bears theory is going.
Then July in Kufra
http://en.wikipedia.org/wiki/Kufra
Check out how awful 0.8º C warming can be.
You could take the MET Office's chums from ZeroCarbonBritain 2030 along with you! It's all taxpayers' money - plenty more where that came from!
Toodlepip!
CAGW groupthink is already being studied by psychologists, but the idea that any insight may lead to collective public/mass immunity to it ignores history, from witchcraft to ozone holes.
It seems public policy lives or dies on the alter of groupthink inspired propaganda.
It doesn't sound from the report that Stocker takes much interest in competing arguments, but then if he regards people who advance such arguments as 'deniers'. then perhaps that is hardly surprising.
The whole bunch of AGW cronies seem to be terrified to even concede that there are competing views and scientific arguments, which in itself is a very telling stance.
"This is quite simply untrue. Most models are fully published. In fact, some of the climategate enquiries reproduced the models in about 2 days."
Zed, you are confusing climate models (large and complex) with temperature reconstructions (small and relatively straight forward). The climate models are usually run on super computers because of the processing load, temperature reconstructions could be run on a PC or even a Mac ;)
[Tone it down please]
Richard Betts, Zed, anybody......
I just want to know how the models work. After all, UK taxpaysers have paid for them, and we are being asked to "bet the farm" on the basis of their output. Is this not a reasonable question?
I could just about understand it if the Met Office did not want to realease the code, as it could be argued that it has commercial value and could recoup some of the taxpayer's investment. However, these models clearly are supported by many volumes of documentation. What could be the possible harm in relaesing the top level documentation that explains the design philosophy and logic?
They aren't fraudsters; the physics is wrong. The question as to whether this was accidental or deliberate is a moot point. Hansen et al's 3.7 times exaggeration of present day GHG warming is highly suspect. Houghton's 1986 unreferenced claim that local thermodynamic equilibrium implies black body radiation from the lower atmosphere is fundamentally wrong but he later refers to grey bodies.
The net result is that CO2-AGW is exaggerated by at least an order of magnitude.
Money, power and prestige need to be studied in any psychological investigation of the present delusion. Each is certain to play a part, with the end word being gold.
The unfolding Morgan Stanley story does tend to be showing gold has a super-attraction.
It is likely to be that simple; the sophistication being the promotion of the required "message" to the, ah... useful idiots?
Quite. As German physicist and meteorologist Klaus-Eckart Puls put it this week:
@ Richard Betts
I don't disagree when you say that not all the members of WG1 attended all the meetings (I mentioned I was possibly being unfair) but it looks very bad.
Suppose (and I accept the analogy is imperfect) that the board of trustees of ASH, while promoting "tobacco control" policies, were all found to be hardened 40-a-day smokers, that they indulged their habit while surrounded by non-smokers, that they made no secret of what they did and no apparent attempt to give up.
I reckon that their credibility would be somewhat damaged. And yet climate scientists do something very similar in travelling the world to meet with other like-minded people in exotic locations, all the while producing large amounts of CO2, a gas which, at least in the "wrong" amount in the "wrong" place, they argue is a grave danger. It almost makes one think that climate scientists may not actually believe what they're saying.
We tend, very sensibly in most cases, to judge others by what they do rather than what they say, and we reserve particular scorn for those who prescribe a certain kind of behaviour while themselves clearly doing otherwise. I at least would be more inclined to believe that climate scientists really believed their own claims if they acted accordingly.
They might begin by, as far as possible, eschewing meetings in places that most other people look on as very good places to take a holiday, so (and with all due respect to the Brussels tourist agency) more Belgium than Bali. Prof Stocker and his ilk could insist that, as far as possible, meetings were carried out by video conferencing or other telecomms means rather than physically transporting tonnes of climate scientists around the continents of the world.
I'm not sure that such changes would necessarily improve the standard of the arguments and evidence for AGW, but sceptics might at least listen more sympathetically if climate scientists walked-the-walk, as I believe the expression is.
May 12, 2012 at 11:02 AM | KnR
Hi, please can you explain what you mean by "places like Blackpool" as distinct from the venues of the author meetings such as Kunming?
One of the main factors in the choice of venue is having a local scientific organisation involved in IPCC to host it. For the author meetings for Working Group 2 (the one I'm in) we met in Tsukuba in January 2011 because that's where a lot of relevant science in Japan is, and then in San Francisco in December because that's where one of the WG2 co-chairs, Chris Field, is based along with the Technical Support Unit. The next meeting, in October, will be in Buenos Airies, where the other WG2 co-chair Vicente Barros is based.
Incidentally, I've never, ever stayed in a 5-star hotel on IPCC business. In fact for AR4 I stayed in a student hall of residence for one of the meetings. Hopefully you'll be pleased to hear that Met Office is very strict on travel expenditure (IPCC or otherwise!).
I should point out that we are only allowed to travel economy class no matter how senior we are or where we are going (even Australia and New Zealand). I've worked for the Met Office for nearly 20 years and they have never, ever bought me a business class ticket!
@Richard, you always seem to be able to pay a flying visit and cheerily demolish a strawman or two when relative trivia (such as air travel) are discussed.
This makes your absence when matters of real importance are aired, such as Briffa's cherry picking of tree ring data, highly questionable..
Would you care to make a defence of Briffa's methodology, or discuss the dangers of type 1 errors in his analysis?
May 12, 2012 at 11:10 AM | Martin Brumby
Hi Martin
As it happens, I wrote about the data on polar bear populations in the WG2 First Order Draft, which was submitted last night :-)
If you want to review it, please email the Technical Support Unit at tsu@ipcc-wg2.gov for registration details.
That wonderful to hear, please can you tell the Met Office's Chief Finance Officer, who seems to think otherwise....!
Cheers
Richard
Ricahrd: Why is the Met Office sponsoring/funding/partnering Zero Carbon Britain?
they are just a bunch of activists (plus special vested interest in renewables.) lobbying for policy (extreme ones at that) ie non-nuclear
It even has Jo Abbess as a renewables contributor..
and my favourite massage therapist, DECC advisor (philosophy grad) contributing to the climate science section (alongside Sir John Houghton)
So WHY does the MET Office have anything to do with such an obvious bunch of activists
One of the team happened 'represented' Kiribati at Copenhagen (a climate youth activists, now with COIN), George Monbiots in there as well.
http://mail.zerocarbonbritain.org/index.php/zcbreportmenu/category/1?download=1%3A2030
Hi Richard,
I believe the point is that the people who are telling the world to cut back CO2 are making not the slightest bit of effort to do so themselves. Commendable though it is that you're not travelling business class you're still flying hither and thither, while people in the movements you're providing the ammunition for are demanding a ban on all flying for everyone (yes I know they're loonies, but then they have managed to get our government to pass a bill spending £18bn/annum for the next twenty years so we can get our emissions down from 3.5 weeks of China's emissions to one week, based on the ammunition provided by the IPCC reports, written by people who don't seem to give a damn about travelling all over the world). One would have thought that in the age of the internet and video conferencing the preparation of reports destined to sway our politicians to reduce the standard of living of our populations so we can share our wealth with dictators in foreign lands flying anywhere except in extremis would be a no-no. (Just in case you don't believe me when I say there are people who want to reduce our standard of living I stopped contributing my hard earned (I'm exaggerating with "hard earned") cash to Oxfam on the basis that that's exactly what they're proposing on the back of climate change).
Don,
I second your comment to Richard (I dare not say it myself, as I have been accused of being rude by some neddy at the Met Office).
I have a horrible, sinking feeling - given his (and everybody else's) deafening silence on the subject - THE MODELS HAVE NO DOCUMENTATION! If this is the case then it is game over.....
If I am wrong I will apologise, but at least this should get a response...
Hi Don,
I've been buried in writing my IPCC chapter until last night so not been able to keep up with the latest developments. I saw that there were posts at Climate Audit, Real Climate and here, but I've not been through them yet.
However, although I'm not sure what it's all about yet, I think it's unlikely that I can comment sensibly on it. I really don't know much about palaeoclimate reconstructions, it's not my area at all so I'm not the right person to try to "defend" things in that field! Try asking Rob Wilson..... :-)
Cheers
Richard
Richard Betts You have been to all those places on tax payers money and the Met office has done the right thing in doing so at the least cost option. The unfortunate thing is that the various COP meetings involving thousands of personnel on taxpayers money have flown first class and stayed at five star hotels and have been partying on tax payers money, to save the world from the tourist class peasant. I am sorry but you will be classed alongside your contemporaries who have indulged themselves however unfair that is.
I do appreciate your involvement on this blog and wish you well.
You cannot apply to the high priests of this Marxist Religion the same behavioural norms you'd expect from the representatives of capital!
Roger Longstaff:
"I just want to know how the models work."
You're not the only one. The met office issued a 3 monthly forecast on 25th March telling us there would be three months of drought, with April being the driest month. 36 days later we were able to announce that April had been it's wettest since records began.
However, I'm reliably assured that the models are better when looking at the weather conditions (aka climate) 50 to 100 years out.
"SUMMARY - PRECIPITATION:
The forecast for average UK rainfall slightly favours drier than average conditions for April/May/June
as a whole, and also slightly favours April being the driest of the 3 months.
With this forecast, the water resources situation in southern, eastern and central England is likely to deteriorate further during the AprilMayJune period.
The probability that UK precipitation for April/May/June will fall into the driest of our five categories is 20/25%
whilst the probability that it will fall into the wettest of our five categories is 10/15% (the 1971/2000
climatological probability for each of these categories is 20%)."
Hi Barry
I don't think the thing with Zero Carbon Britain is still happening, and I'm pretty sure the Met Office was not funding them.
We do work with the renewables sector in terms of providing weather and climate advice, but also with oil and coal too (and nuclear).
Cheers
Richard
"Try asking Rob Wilson..... :-)"
Nice one Richard, I take it you saw our interchange with Rob. He came across as someone who saw himself as yummy." If he was made of chocolate he'd probably eat himself." (Scottish saying, anon)
Roger Longtaff
Actually the models are extensively documented!
The latest version of the Met Office Hadley Centre climate model is published in the peer-reviewed, open-access literature here, here and here, and the underlying technical documentation for the latest version of the core numerical model is here.
Anyway, got to go I'm afraid, it's a lovely day and I've been stuck indoors writing a lot lately so I'm going to go and sort the garden out...!
:-)
Cheers
Richard
geronimo; you haven't got the point, you norty boy. The aim of the weather forecasts is not to forecast weather, it's to maintain in the Public Mind that CO2-AGW is dangerous and is changing the climate.
So, they're claiming it's becoming warmer and more extreme..This is why the drought was so important to them, and it's being let go with great reluctance. In the US, Hansen is claiming permanent drought-flood.in their South West.
I do wish I could get hold of the FSB's briefing documents to their agents in the West......
The question with respect to Zero Carbon Britain was why were involved in the first place..
Why was there ever a connection the Met Office lent their name to it (and credibility) to give it some authority?
CAT, and Zero Carbon are lobbyists for Energy policy... Met Office should not be seen lobbying for policy.
Richard,
Many thanks for the references. I apologise for doubting you and I will look at them with interest
Have fun in the garden.
@ Richard Betts, Roger Longstaff
I thought the interesting point from Prof Stocker's talk wasn't whether or not (or indeed how) the models work, but that he didn't mention that the best way to test them was to compare their predictions with measurements (of physical quantities, not other model outputs). He seemed to think that mutual comparison and attendant "uncertainty" was an appropriate way to inform policy-makers of the range of likely future climates. It seemed like a navel-gazing approach.
I think the Met Office assesses the quality of the their weather forecasts by seeing how much better they are than just assuming the weather tomorrow will be the same as today's (that doesn't strike me as setting the bar very high - they could at least use seaweed as a benchmark) so there is a quantitative measure of how well they're doing. You can, for example, see how performance falls off as the prediction time gets later. I wonder which climate models have been assessed in an analogous way and how well they've done.
Now I too must cultivate my garden (or at any rate do some hacking and trimming).
There is nothing wrong with the GCMs in respect of the solution of the Navier-Stokes' equations. What is wrong is grossly exaggerated IR warming at the earth's surface, BB radiation from the cooler atmosphere to the Earth and the absence of the crucial 29 ° C upper limit to ocean temperature, which is when exponentially increasing evaporation effectively causes extra IR emission to fall near zero.
I've just come across a climate fact sheet:
http://pirc.info/Climate_Factsheets_PIRC.pdf?utm_medium=email&utm_campaign=Factsheets&utm_content=Factsheets+CID_48dd84d10b70d1fe184c8f4c10914868&utm_source=Newsletter&utm_term=DOWNLOAD
an example..
"Average global temperature has increased
by around 0.75ºC since the beginning of the
20th century. Most of this is very likely to be
due to human greenhouse gas emissions."
------------------
Spot the problem I have with it?
Define MOST....
50%-95%?
As far as I'm aware, even IPCC say half natural..
A very disengenuous aricle, implying near ALL 20th century warming is AGW, very carefully worded. Vicky Pope, Phil Jones, K Hayhoe, Sir John Houghton, Hansen all put their names to it.
Lots of sections with 'What Sceptics Say'
A fact sheet , by the PIRC.. with lots of the climate concerned involved
I think I can help Barry, it's not 50% that would be half, so it's 51% to 99%. I seem to remember the IPCC said half, but they only did that through the models anyway, there's no empirical proof. Shame on them all.